Photo-detector filter

ABSTRACT

Method and systems related to obstructing a first predefined portion of at least one defined wavelength of light incident upon a first photo-detector array; and detecting the at least one defined wavelength of light with a photo-detector in a second photo-detector array.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is related to and claims the benefit of theearliest available effective filing date(s) from the following listedapplication(s) (the “Related Applications”) (e.g., claims earliestavailable priority dates for other than provisional patent applicationsor claims benefits under 35 USC §119(e) for provisional patentapplications, for any and all parent, grandparent, great-grandparent,etc. applications of the Related Application(s)), and incorporates byreference in its entirety all subject matter of the following listedapplication(s) (in the event of any inconsistencies between the instantapplication and an application incorporated by reference, the instantapplication controls):

1. For purposes of the USPTO extra-statutory requirements, the presentapplication constitutes a continuation of U.S. patent application Ser.No. 11/236,414 entitled PHOTO-DETECTOR FILTER, naming W. Daniel Hillis,Roderick A. Hyde, Nathan P. Myhrvold, and Lowell L. Wood, Jr. asinventors, filed on Sep. 27, 2005, which is scheduled to issue as U.S.Pat. No. 7,542,133 on Jun. 2, 2009, or is an application of which acurrently co-pending application is entitled to the benefit of thefiling date.

2. For purposes of the USPTO extra-statutory requirements, the presentapplication constitutes a continuation-in-part of U.S. patentapplication Ser. No. 10/744,057 entitled PHOTO-DETECTOR FILTER, namingW. Daniel Hillis, Roderick A. Hyde, Nathan P. Myhrvold, and Lowell L.Wood, Jr. as inventors, filed on Dec. 22, 2003, now issued as U.S. Pat.No. 7,053,998 on May 30, 2006, and which is an application of which acurrently co-pending application is entitled to the benefit of thefiling date.

3. For purposes of the USPTO extra-statutory requirements, the presentapplication constitutes a continuation-in-part of U.S. patentapplication Ser. No. 10/744,058 entitled AUGMENTED PHOTO-DETECTORFILTER, naming W. Daniel Hillis, Roderick A. Hyde, Nathan P. Myhrvold,and Lowell L. Wood, Jr. as inventors, filed on Dec. 22, 2003, now issuedas U.S. Pat. No. 7,098,439 on Aug. 29, 2006, and which is an applicationof which a currently co-pending application is entitled to the benefitof the filing date.

The United States Patent Office (USPTO) has published a notice to theeffect that the USPTO's computer programs require that patent applicantsreference both a serial number and indicate whether an application is acontinuation or continuation-in-part. Stephen G. Kunin, Benefit ofPrior-Filed Application, USPTO Official Gazette Mar. 18, 2003. Thepresent Applicant Entity (hereinafter “Applicant”) has provided above aspecific reference to the application(s) from which priority is beingclaimed as recited by statute. Applicant understands that the statute isunambiguous in its specific reference language and does not requireeither a serial number or any characterization, such as “continuation”or “continuation-in-part,” for claiming priority to U.S. patentapplications. Notwithstanding the foregoing, Applicant understands thatthe USPTO's computer programs have certain data entry requirements, andhence Applicant is designating the present application as acontinuation-in-part of its parent applications as set forth above, butexpressly points out that such designations are not to be construed inany way as any type of commentary and/or admission as to whether or notthe present application contains any new matter in addition to thematter of its parent application(s). All subject matter of the RelatedApplications and of any and all parent, grandparent, great-grandparent,etc. applications of the Related Applications is incorporated herein byreference to the extent such subject matter is not inconsistentherewith.

TECHNICAL FIELD

The present application relates, in general, to photo-detector systems.

SUMMARY

In one aspect, a system includes but is not limited to: a firstphoto-detector array configured to obstruct a first predefined portionof at least one defined wavelength of light impinging upon said firstphoto-detector array; and a second photo-detector array sensitive to theat least one defined wavelength of light, said second photo-detectorarray positioned proximate to said first photo-detector array. Otherrelated system aspects are shown and described elsewhere herein.

In one aspect, a method of constructing a system includes but is notlimited to: forming a first photo-detector array configured to obstructa first predefined portion of at least one defined wavelength of lightimpinging thereupon; and forming a second photo-detector array sensitiveto the at least one defined wavelength of light in a vicinity of thefirst photo-detector array. Other related method aspects are shown anddescribed elsewhere herein.

In one aspect, a method of detecting light includes but is not limitedto: obstructing a first predefined portion of at least one definedwavelength of light incident upon a first photo-detector array; anddetecting the at least one defined wavelength of light with aphoto-detector in a second photo-detector array.

In one or more various aspects, related systems include but are notlimited to circuitry and/or programming for effecting the method aspectsdescribed in the text and/or drawings of the present application; thecircuitry and/or programming can be virtually any combination ofhardware, software, and/or firmware configured to effect theforegoing-referenced method aspects depending upon the design choices ofthe system designer.

Various other method and or system aspects are set forth and describedin the text (e.g., claims and/or detailed description) and/or drawingsof the present application.

The foregoing is a summary and thus contains, by necessity;simplifications, generalizations and omissions of detail; consequently,those skilled in the art will appreciate that the summary isillustrative only and is NOT intended to be in any way limiting. Otheraspects, inventive features, and advantages of the devices and/orprocesses described herein, as defined solely by the claims, will becomeapparent in the non-limiting detailed description set forth herein.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the invention, together with features and advantages thereof,may be understood by making reference to the following description takenin conjunction with the accompanying drawings, in the several figures ofwhich like referenced numerals identify like elements, and wherein:

FIG. 1 shows structure 100 that includes photo-detector arrays 102, 104,and 106.

FIG. 2 depicts system 200 that includes the subject matter shown in FIG.1.

FIG. 3 depicts system 200 that includes the subject matter shown in FIG.1.

FIG. 4 shows structure 400 that constitutes an alternate implementationof structure 100.

The use of the same symbols in different drawings typically indicatessimilar or identical items.

DETAILED DESCRIPTION

In the following detailed description of exemplary embodiments,reference is made to the accompanying drawings, which form a parthereof. In the several figures, like referenced numerals identify likeelements. The detailed description and the drawings illustrate exemplaryembodiments. Other embodiments may be utilized, and other changes may bemade, without departing from the spirit or scope of the subject matterpresented here. The following detailed description is therefore not tobe taken in a limiting sense, and the scope of the claimed subjectmatter is defined by the appended claims.

With reference to the figures, and with reference now to FIG. 1, shownis structure 100 that includes photo-detector arrays 102, 104, and 106.Example implementations of photo-detector arrays 102, 104, and 106include but are not limited to charge coupled device (CCD) sensorarrays, complementary metal oxide semiconductor (CMOS) sensor arrays,and/or mixtures of CCD and CMOS arrays. Those having skill in the artmay substitute other suitable types of photo-detector arrays in view ofthe teachings herein with a reasonable amount of experimentation.

Photon groups 108, 110, and 112 are depicted as respectively impingingupon photo-detectors 114, 116, and 118 of photo-detector array 102.Photo-detector array 102 is depicted as configured to obstruct apredefined portion of at least one defined wavelength of light impingingupon photo-detector array 102. As one specific example, photo-detectors114, 116, and 118 of photo-detector array 102 are illustrated asobstructing ½, or 50%, of the photons of photon groups 108, 110, and 112impinging upon photo-detector array 102. (While the examples herein areshown in terms of integral numbers of photons for clarity ofpresentation, those skilled in the art will recognize that otherrelative measures of brightness, intensity, power density, and/or otherproperties of light exist; specifically, those having skill in the artwill recognize that the response of specific devices may operate on asquare law format, straight linear format, or other format.) Thoseskilled in the art will recognize that the obstruction level of 50%discussed herein is illustrative only, and that different obstructionlevels are possible. Similarly, those skilled in the art will recognizethat the obstruction level may be chosen to be different in some or allof the specific photodetectors.

Unobstructed portions 120, 122, 124 of photon groups 108, 110, and 112,respectively, are shown impinging upon photo-detectors 126, 128, and 130of photo-detector array 104. Photo-detector array 104 is depicted asconfigured to obstruct a predefined portion of at least one definedwavelength of light impinging upon photo-detector array 104. As onespecific example, photo-detectors 126, 128, and 130 of photo-detectorarray 104 are illustrated as obstructing ½, or 50%, of the photons ofportions 120, 122, and 124 of light impinging upon photo-detector array104.

Unobstructed portions 132, 134, and 136 of portions 120, 122, and 124,respectively, are shown impinging upon photo-detectors 138, 140, and 142of photo-detector array 106. Photo-detector array 106 is depicted asconfigured to obstruct a predefined portion of at least one definedwavelength of light impinging upon photo-detector detector array 106. Asone specific example, photo-detectors 138, 140, and 142 ofphoto-detector array 106 are illustrated as obstructing ½, or 50%, ofthe photons of portions 132, 134, and 136 impinging upon photo-detectorarray 106.

There are multiple advantages arising from structure 100. A few of theseadvantages will now be explicitly discussed in the context of processesshown and/or described in relation to FIGS. 2 and 3. For example,insofar as the predetermined portions obstructed and/or unobstructed byphoto-detector arrays 102, 104, and 106 are known, the array levels atwhich light is detected will allow strong inferences to be made as tothe intensity of photon groups 108, 110, and 112 respectively impingingupon photo-detectors 114, 116, and 118 of photo-detector array 102.Another advantage is that, insofar as photo-detector arrays 102, 104,and 106 are layered, the various layers may provide for more accuracy.Yet another advantage is that, insofar as photo-detector arrays 102,104, and 106 are layered, the various layers may extend the dynamicrange far beyond the saturation point of the photo-detectors in upperlevel photo-detectors, such as the photo-detectors in photo-detectorarray 102.

Referring now to FIG. 2, depicted is system 200 that includes thesubject matter shown in FIG. 1. System 200 may form an environment for aprocess that serves to illustrate a few of the advantages of structure100. As a specific example, shown following is that, in the event thatthe photo-detectors of photo-detector arrays 102, 104, and 106 are suchthat they saturate after the incidence of 6 photons, structure 100 willallow an image to be gathered that exceeds the saturation point of thephoto-detectors of uppermost photo-detector array 102. Specifically,although the photo-detectors saturate after 6 photons, the example ofFIG. 2 shows that intensity at photo-detector array 102 can be inferredbeyond the dynamic range of photo-detector array 102.

Charge detectors 238, 226, and 214 are shown as coupled to detect thecharge in photo-detectors 138, 126, and 114, respectively. Brightnessinference units 2380, 2260, and 2140 are shown as coupled to calculatethe intensity indicated by charge detectors 238, 226, and 214,respectively. Although only a few specific charge detector-brightnessinference unit combinations are shown and described herein, those havingskill in the art will recognize that, in most implementations, generallymost photodetectors in use will be coupled to one or more similar chargedetector-brightness inference unit combinations, which will thereaftercouple with one or more brightness inference selection units 2500. Thosehaving skill in the art will recognize that the teaching herein can beextended to virtually all suitable photo-detector arrays, including butnot limited to Vertical, Linear, Interline, Full-frame, andFrame-transfer arrays via a reasonable amount of experimentation. Theconventional aspects of such photo-detector architectures are notdescribed herein for sake of brevity.

Charge detector 238 is depicted as coupled to detect the charge inphoto-detector 138. Charge detector 238 is further shown as coupled tobrightness inference unit 2380. Brightness inference unit 2380 hasknowledge of photo-detector 106's relative place in the stack and thepredetermined light obstruction/unobstruction characteristics of thephoto-detectors in the stack above photo-detector 106. Accordingly,brightness inference unit 2380 can calculate a likely intensity ofphoton-group 108 impinging on uppermost photo-detector array 102. As aspecific example, the fact that photo-detector 126 of photo-detectorarray 104 is known to obstruct ½, or 50%, of its incidentphotons—coupled with the information from charge detector 238 that 2photons have impinged upon photo-detector 138—allows brightnessinference unit 2380 to calculate that approximately four photons wereincident upon photo-detector 126. Brightness inference unit 2380 canthereafter use this 4-photon inference coupled with the fact thatphoto-detector 114 of photo-detector array 102 is known to obstruct ½,or 50%, of its incident photons to calculate that approximately 8photons were incident upon photo-detector 114.

Charge detector 226 and brightness inference unit 2260 are depicted asworking in a fashion similar to charge detector 238 and brightnessinference unit 2380 to calculate that the 4 photons received byphoto-detector 126 indicate that approximately 8 photons were receivedby photo-detector 114.

Charge detector 214 and brightness inference unit 2140 are illustratedas working in a fashion similar to charge detector 238 and brightnessinference unit 2380 to calculate that the 8 photons received byphoto-detector 114 indicate that approximately 6 photons were receivedby photo-detector 114, since photo-detector 114—for sake of example—isassumed to saturate at 6 photons.

Brightness inference selection unit 2500 is shown as coupled to receivethe results of brightness inference units 2380, 2260, and 2140.Brightness inference selection unit 2500 runs various selection routinesto determine which of brightness inference units 2380, 2260, and 2140are likely most accurate. Continuing with the present example,brightness inference selection unit 2500 would note that brightnessinference unit 2140's calculation was at the threshold saturation pointof photo-detector 114, and would mark that calculation as suspect.Thereafter, brightness inference selection unit 2500 would note thatbrightness inference unit 2260's and 2380's calculations were below thethreshold saturation point of photo-detector 114. Consequently,brightness inference selection unit 2500 would average brightnessinference unit 2260's and 2380's calculations (ignoring brightnessinference unit 2140's at-threshold calculation) to get a brightnessinference of 8 photons.

Brightness inference selection unit 2500 is depicted as coupled toconventional display circuitry 2502. Conventional display circuitry 2502typically expects to receive one of a number of discrete signalsindicative of pixel brightness (what those signals are constitutes aconventional design choice). Continuing with the present example,brightness inference selection unit 2500 generates a signal indicativeof 8 photon brightness and delivers that signal over to conventionaldisplay circuitry 2502, which then uses the signal in a conventionalfashion to produce an image representation.

With reference now to FIG. 3, depicted is system 200 that includes thesubject matter shown in FIG. 1. System 200 may form an environment for aprocess that serves to illustrate of few of the advantages of structure100. As a specific example, shown following is that, in the event thatphoton group 110 is such that there is “quantization error” introducedby the filtering photo-detectors, the fact that there are multiplelayers of filters allows system 200 to increase the likelihood that such“quantization errors” can be corrected.

Charge detector 340 is depicted as coupled to detect the charge inphoto-detector 140. Charge detector 340 is further shown as coupled tobrightness inference unit 3400. Brightness inference unit 3400 hasknowledge of photo-detector array 106's (e.g., photo-detector 140's)relative place in the stack and the predetermined lightobstruction/unobstruction characteristics of the photo-detectors in thestack above photo-detector array 106 (photo-detector 140). Accordingly,brightness inference unit 3400 can calculate a likely intensity ofphoton-group 110 impinging on uppermost photo-detector array 102. As aspecific example, the fact that photo-detector 128 of photo-detectorarray 104 is known to obstruct ½, or 50%, of its incidentphotons—coupled with the information from charge detector 340 that 1photon has impinged upon photo-detector 140—allows brightness inferenceunit 3400 to calculate that approximately 2 photons were incident uponphoto-detector 128; unfortunately, since the 1 photon impinging uponphoto-detector 140 is the result of photo-detector 128 filtering 50% of3 photons, there is quantization error in the filtering which makes thiscalculated intensity of the light at photo-detector array 104 lessaccurate than without the quantization error. Brightness inference unit3400 can thereafter use this 2-photon inference coupled with the factthat photo-detector 116 of photo-detector array 102 is known to obstruct½, or 50%, of its incident photons to calculate that approximately 4photons were incident upon photo-detector 116.

Charge detector 328 and brightness inference unit 3280 are depicted asworking in a fashion similar to charge detector 340 and brightnessinference unit 3400. Brightness inference unit 3280 has knowledge ofphoto-detector array 104's (e.g., photo-detector 128's) relative placein the stack and the predetermined light obstruction/unobstructioncharacteristics of the photo-detector in the stack above photo-detector104 (e.g., photo-detector 128). Accordingly, brightness inference unit3280 can calculate a likely intensity of photon-group 110 impinging onuppermost photo-detector array 102. Continuing with the present example,the fact that photo-detector 116 of photo-detector array 102 is known toobstruct ½, or 50%, of the photons, coupled with the information fromcharge detector 328 that 3 photons has impinged upon photo-detector 128allows brightness inference unit 3280 to calculate that approximately 6photons were incident upon photo-detector 116. Brightness inference unit3280 can thereafter use this 6-photon inference coupled with the factthat photo-detector 116 of photo-detector array 102 is known to obstruct½, or 50%, of the photons to calculate that approximately 6 photons wereincident upon photo-detector 116.

Charge detector 316 and brightness inference unit 3160 are illustratedas working in a fashion similar to charge detector 340 and brightnessinference unit 3400 to calculate that the 6 photons received byphoto-detector 116 indicate that approximately 6 photons were receivedby photo-detector 116.

Brightness inference selection unit 2500 is shown as coupled to receivethe results of brightness inference units 3400, 3280, and 3160.Brightness inference selection unit 2500 runs various selection routinesto determine which of brightness inference units 3400, 3280, and 3160are likely most accurate. Continuing with the present example,brightness inference selection unit 2500 would note that brightnessinference unit 3160's calculation was at the threshold saturation pointof photo-detector 114, and would mark that calculation as suspect.Thereafter, brightness inference selection unit 2500 would note thatbrightness inference unit 3280's and 3400's calculations do not agree.Consequently, brightness inference selection unit 2500 would detect thatbrightness inference unit 3280's calculation matched brightnessinference unit 3160's calculation, even though brightness inference unit3160's calculation shows a threshold saturation value; accordingly,brightness inference selection unit would treat brightness inferenceunit 3160's calculation as accurate and then average all threecalculations of brightness inference units 3400, 3280, and 3160 (e.g.,(4+6+6)/3=5.33) to select a brightness inference of 6 photons as mostlikely; alternatively, the fact that brightness inference unit 3280makes its threshold inference based on more collected charge (e.g., asindicated by charge detector 328) than the charge collected by lowermostbrightness inference unit 3400 could be used to decide that brightnessinference unit 3280's was the more accurate. Those having skill in theart will appreciate other selection routines in light of the teachingsherein.

Photo-detector arrays 102, 104, 106 have been described herein asconfigured to obstruct predefined portions of at least one definedwavelength of light impinging upon photo-detector arrays 102, 104, 106.There are many different ways in which such photo-detector arrays may beimplemented. In some implementations of the photo-detector arrays, atleast one photo-detector is constructed to provide an optical filterhaving a passband including at least one of a red, a blue, and a greenvisible light wavelength. Exemplary implementations includephoto-detectors constructed to filter red, blue, and green visible lightwavelengths either individually or in some combination thereof. Otherexemplary implementations include photo-detectors constructed to filter400 through 800 nm wavelengths of light either individually or in somecombination thereof.

In other implementations of the photo-detector arrays, at least onephoto-detector is constructed to provide a substantially neutral densityfilter (neutral density filters attenuate incident light withoutsignificantly altering its spectral distribution over a defined group ofwavelengths of interest). In one exemplary implementation, one or morephoto-detectors are constructed to provide a neutral density filter thatdecreases an intensity of light energy without substantially altering arelative spectral distribution of an unobstructed portion of the lightenergy. In another exemplary implementation, one or more photo-detectorsare constructed to provide a substantially neutral density filter thatfilters an entire visible spectrum substantially evenly withoutsubstantially influencing at least one of color and contrast of anunobstructed portion of the entire visible spectrum. In anotherexemplary implementation, one or more photo-detectors are constructed toprovide a substantially neutral density filter that utilizes at leastone of absorption and reflection. In another exemplary implementation,one or more photo-detectors are constructed to provide a substantiallyneutral density filter that filters substantially ½ of the lightimpinging upon the photo-detectors. In another exemplary implementation,one or more photo-detectors are constructed to provide a substantiallyneutral density filter that filters a defined portion of photons atleast partially composing the light impinging upon said firstphoto-detector. The examples herein are not intended to be exhaustive,and those having skill in the art may substitute other types ofphoto-detector arrays in view of the teachings herein with a reasonableamount of experimentation.

Referring now to FIG. 4, shown is structure 400 that constitutes analternate implementation of structure 100. Spectrally dependent filter402 is depicted interposed between photo-detector array 102 andphoto-detector array 104. Those skilled in the art will recognize thatspectrally-dependent filter 402 can be either monolithic (as shown inFIG. 4), or can be spatially differentiated using either the samepixilation pattern as in photo-detector arrays 102 or 104, or using adifferent pattern. Although only two photo-detector arrays and onespectrally-dependent filter are shown in FIG. 4, structure 400 isintended to be representative of its shown components repeated manytimes, and is also intended to be representative of a composite ofstructures 100 of FIG. 1 and structure 400 of FIG. 4. In addition,although not explicitly shown, it will be appreciated by those havingskill in the art that FIGS. 2 and 3 can be modified to include andutilize the subject matter of FIG. 4 with a routine amount ofexperimentation.

In one implementation, spectrally dependent filter 402 can be depictedinterposed between photo-detector array 102 and photo-detector array104. Spectrally dependent filter is used to equalize the filtering ofphoto-detector array 102 so that the various wavelengths of portions120, 122, 124 have been like filtered prior to impinging uponphoto-detector 104. For example, in some implementations, photo-detectorarray 102 will not provide a true neutral density filter function acrossred, blue, and green wavelength light. Specifically, assume thatphoto-detector 102 allowed 50% of the red and blue light to pass butallowed 60% of the green light to pass. In such a situation,spectrally-dependent filter 402 would provide an additional green filterso that the red, blue, and green light were all filtered approximately50% when they reached photo-detector 104.

In another implementation, spectrally dependent filter 402 can bedesigned to attenuate at least one first wavelength (e.g., blue light)substantially more than at least one second wavelength (e.g., redlight). In such a situation, the difference between signals detected byphoto-detector array 104 and photo-detector array 102, can be used todetermine the spectral composition of light impinging upon the device400.

In another example implementation of spectrally-dependent filter 402,spectrally-dependent filter 402 is constructed to filter at least onedefined wavelength of light between about 400 and about 800 nano-meters.

In one example implementation of structure 400, photo-detector arraysproximate to each other are constructed of different semi-conductormaterials.

In another example implementation of structure 400, spectrally-dependentfilter 402 is made from a semi-conductor material that is the same asthe material used in at least one of the first and second photo-detectorarrays, the semiconductor material having at least one of a dopingmaterial and a concentration chosen to meet a predefined amount ofoptical obstruction; in an alternate implementation, the material isdifferent from that of a photo-detector array proximate tospectrally-dependent filter 402.

In another example implementation of structure 400, spectrally-dependentfilter 402 provides its filtering/obstruction properties via at leastone of absorption and reflection mechanisms.

In another example implementation of structure 400, spectrally-dependentfilter 402 provides an amount of obstruction substantially different forat least one second defined wavelength of light than for the at leastone defined wavelength of light which photo-detector 102 has beenconfigured to obstruct.

In another example implementation of structure 400, spectrally-dependentfilter 402 provides an amount of obstruction substantially the same fora defined set of wavelengths, the set containing the first definedwavelength of light.

In another example implementation of structure 400, at least onephoto-detector in a photo-detector array substantially matches at leastone of the size, shape, and lateral location of at least onephoto-detector in another photo-detector array.

In another example implementation of structure 400, at least onephoto-detector in one photo-detector array is in respective substantialalignment with a plurality of photo-detectors in another photo-detectorarray.

In another example implementation of structure 400, the photo-detectorarrays are each permeable to a first and a second defined wavelength oflight.

In another example implementation of structure 400, structure 400contains a set of N+1 photo-detector arrays, each pair of which isproximate to and separated by an optical filter, such that relativeoptical spectrums entering N of the photo-detector arrays aresubstantially different from each other, and such that a relativeoptical spectrum entering photo-detector array N+1 has a substantiallysimilar relative spectrum as that relative spectrum entering the firstphoto-detector array.

The foregoing detailed description has set forth various embodiments ofthe devices and/or processes via the use of block diagrams, flowcharts,and examples. Insofar as such block diagrams, flowcharts, and examplescontain one or more functions and/or operations, it will be understoodas notorious by those within the art that each function and/or operationwithin such block diagrams, flowcharts, or examples can be implemented,individually and/or collectively, by a wide range of hardware, software,firmware, or virtually any combination thereof. In one embodiment, thepresent invention may be implemented via Application Specific IntegratedCircuits (ASICs), Field Programmable Gate Arrays (FPGAs), or otherintegrated formats. However, those skilled in the art will recognizethat the embodiments disclosed herein, in whole or in part, can beequivalently implemented in standard integrated circuits, as one or morecomputer programs running on one or more computers (e.g., as one or moreprograms running on one or more computer systems), as one or moreprograms running on one or more processors (e.g., as one or moreprograms running on one or more microprocessors), as firmware, or asvirtually any combination thereof, and that designing the circuitryand/or writing the code for the software and or firmware would be wellwithin the skill of one skilled in the art in light of this disclosure.In addition, those skilled in the art will appreciate that themechanisms of the present invention are capable of being distributed asa program product in a variety of forms, and that an illustrativeembodiment of the present invention applies equally regardless of theparticular type of signal bearing media used to actually carry out thedistribution. Examples of a signal bearing media include, but are notlimited to, the following: recordable type media such as floppy disks,hard disk drives, CD ROMs, digital tape, and computer memory; andtransmission type media such as digital and analog communication linksusing TDM or IP based communication links (e.g., packet links).

In a general sense, those skilled in the art will recognize that thevarious embodiments described herein which can be implemented,individually and/or collectively, by various types of electro-mechanicalsystems having a wide range of hardware, software, firmware, orvirtually any combination thereof. Consequently, as used herein“electrical system” includes, but is not limited to, electricalcircuitry operably coupled with a transducer (e.g., an actuator, amotor, a piezoelectric crystal, etc.), electrical circuitry having atleast one discrete electrical circuit, electrical circuitry having atleast one integrated circuit, electrical circuitry having at least oneapplication specific integrated circuit, electrical circuitry forming ageneral purpose computing device configured by a computer program (e.g.,a general purpose computer configured by a computer program which atleast partially carries out processes and/or devices described herein,or a microprocessor configured by a computer program which at leastpartially carries out processes and/or devices described herein),electrical circuitry forming a memory device (e.g., forms of randomaccess memory), electrical circuitry forming a communications device(e.g., a modem, communications switch, or optical-electrical equipment),and any non-electrical analog thereto, such as optical or other analogs.

Those skilled in the art will recognize that it is common within the artto describe devices and/or processes in the fashion set forth herein,and thereafter use standard engineering practices to integrate suchdescribed devices and/or processes into image processing systems. Thatis, at least a portion of the devices and/or processes described hereincan be integrated into an image processing system via a reasonableamount of experimentation. Those having skill in the art will recognizethat a typical image processing system generally includes one or more ofa system unit housing, a video display device, a memory such as volatileand non-volatile memory, processors such as microprocessors and digitalsignal processors, computational entities such as operating systems,drivers, and applications programs, one or more interaction devices,such as a touch pad or screen, control systems including feedback loopsand control motors (e.g., feedback for sensing lens position and/orvelocity; control motors for moving/distorting lenses to give desiredfocuses. A typical image processing system may be implemented utilizingany suitable commercially available components, such as those typicallyfound in digital still systems and/or digital motion systems.

The foregoing described embodiments depict different componentscontained within, or connected with, different other components. It isto be understood that such depicted architectures are merely exemplary,and that in fact many other architectures can be implemented whichachieve the same functionality. In a conceptual sense, any arrangementof components to achieve the same functionality is effectively“associated” such that the desired functionality is achieved. Hence, anytwo components herein combined to achieve a particular functionality canbe seen as “associated with” each other such that the desiredfunctionality is achieved, irrespective of architectures or intermedialcomponents. Likewise, any two components so associated can also beviewed as being “operably connected” or “operably coupled” to each otherto achieve the desired functionality.

While particular embodiments of the present invention have been shownand described, it will be understood by those skilled in the art that,based upon the teachings herein, changes and modifications may be madewithout departing from this invention and its broader aspects and,therefore, the appended claims are to encompass within their scope allsuch changes and modifications as are within the true spirit and scopeof this invention. Furthermore, it is to be understood that theinvention is solely defined by the appended claims. It will beunderstood by those within the art that, in general, terms used herein,and especially in the appended claims (e.g., bodies of the appendedclaims) are generally intended as “open” terms (e.g., the term“including” should be interpreted as “including but not limited to,” theterm “having” should be interpreted as “having at least,” the term“includes” should be interpreted as “includes but is not limited to,”“comprise” and variations thereof, such as, “comprises” and “comprising”are to be construed in an open, inclusive sense, that is as “including,but not limited to,” etc.). It will be further understood by thosewithin the art that if a specific number of an introduced claimrecitation is intended, such an intent will be explicitly recited in theclaim, and in the absence of such recitation no such intent is present.For example, as an aid to understanding, the following appended claimsmay contain usage of the introductory phrases “at least one” and “one ormore” to introduce claim recitations. However, the use of such phrasesshould NOT be construed to imply that the introduction of a claimrecitation by the indefinite articles “a” or “an” limits any particularclaim containing such introduced claim recitation to inventionscontaining only one such recitation, even when the same claim includesthe introductory phrases “one or more” or “at least one” and indefinitearticles such as “a” or “an” (e.g., “a” and/or “an” should typically beinterpreted to mean “at least one” or “one or more”); the same holdstrue for the use of definite articles used to introduce claimrecitations. In addition, even if a specific number of an introducedclaim recitation is explicitly recited, those skilled in the art willrecognize that such recitation should typically be interpreted to meanat least the recited number (e.g., the bare recitation of “tworecitations,” without other modifiers, typically means at least tworecitations, or two or more recitations).

1. A system comprising: a first photo-detector configured to obstruct afirst predefined portion of at least one defined wavelength of lightimpinging upon said first photo-detector; and a second photo-detectorsensitive to the at least one defined wavelength of light, said secondphoto-detector being positioned along a path of unobstructed lightpassing through the first photo-detector onto the second photo-detector.2. The system of claim 1, wherein said first photo-detector configuredto obstruct a first predefined portion of at least one definedwavelength of light impinging upon said first photo-detector comprises:at least one of a charge coupled device (CCD) or a complementary metaloxide semiconductor (CMOS).
 3. The system of claim 1, wherein said firstphoto-detector configured to obstruct a first predefined portion of atleast one defined wavelength of light impinging upon said firstphoto-detector comprises: at least one photo-detector constructed toprovide an optical filter having a passband including at least one of ared, a blue, and a green visible light wavelength.
 4. The system ofclaim 1, wherein said first photo-detector configured to obstruct afirst predefined portion of at least one defined wavelength of lightimpinging upon said first photo-detector comprises: at least onephoto-detector constructed to provide a substantially neutral densityfilter.
 5. The system of claim 1, wherein said first photo-detectorconfigured to obstruct a first predefined portion of at least onedefined wavelength of light impinging upon said first photo-detectorcomprises: at least one photo-detector constructed to provide asubstantially neutral density filter that decreases an intensity oflight energy without substantially altering a relative spectraldistribution of an unobstructed portion of the light energy.
 6. Thesystem of claim 1, wherein said first photo-detector configured toobstruct a first predefined portion of at least one defined wavelengthof light impinging upon said first photo-detector comprises: at leastone photo-detector constructed to provide a substantially neutraldensity filter that filters an entire visible spectrum substantiallyevenly without substantially influencing at least one of color andcontrast of an unobstructed portion of the entire visible spectrum. 7.The system of claim 1, wherein said first photo-detector configured toobstruct a first predefined portion of at least one defined wavelengthof light impinging upon said first photo-detector comprises: at leastone photo-detector constructed to provide a substantially neutraldensity filter that utilizes at least one of absorption and reflection.8. The system of claim 1, wherein said first photo-detector configuredto obstruct a first predefined portion of at least one definedwavelength of light impinging upon said first photo-detector comprises:at least one photo-detector constructed to provide a substantiallyneutral density filter that filters substantially ½ of the lightimpinging upon said first photo-detector.
 9. The system of claim 1,wherein said first photo-detector configured to obstruct a firstpredefined portion of at least one defined wavelength of light impingingupon said first photo-detector comprises: at least one photo-detectorconstructed to provide a substantially neutral density filter thatfilters a defined portion of photons at least partially composing thelight impinging upon said first photo-detector.
 10. The system of claim1, wherein said second photo-detector sensitive to the at least onedefined wavelength of light, said second photo-detector being positionedalong a path of unobstructed light passing through the firstphoto-detector onto the second photo-detector comprises: a secondphoto-detector configured to obstruct a second predefined portion of theat least one defined wavelength of light impinging upon said secondphoto-detector.
 11. The system of claim 10, wherein said secondphoto-detector configured to obstruct a second predefined portion of theat least one defined wavelength of light impinging upon said secondphoto-detector comprises: at least one of a charge coupled device (CCD)array or a complementary metal oxide semiconductor (CMOS) array.
 12. Thesystem of claim 10, wherein said second photo-detector configured toobstruct a second predefined portion of the at least one definedwavelength of light impinging upon said second photo-detector comprises:at least one photo-detector constructed to provide an optical filterhaving a passband including at least one of a red, a blue, and a greenvisible light wavelength.
 13. The system of claim 10, wherein saidsecond photo-detector configured to obstruct a second predefined portionof the at least one defined wavelength of light impinging upon saidsecond photo-detector comprises: at least one photo-detector constructedto provide a substantially neutral density filter.
 14. The system ofclaim 10, wherein said second photo-detector configured to obstruct asecond predefined portion of the at least one defined wavelength oflight impinging upon said second photo-detector comprises: at least onephoto-detector constructed to provide a substantially neutral densityfilter that decreases an intensity of light energy without substantiallyaltering a relative spectral distribution of an unobstructed portion ofthe light energy.
 15. The system of claim 10, wherein said secondphoto-detector configured to obstruct a second predefined portion of theat least one defined wavelength of light impinging upon said secondphoto-detector comprises: at least one photo-detector constructed toprovide a substantially neutral density filter that filters an entirevisible spectrum substantially evenly without substantially influencingat least one of color and contrast of an unobstructed portion of theentire visible spectrum.
 16. The system of claim 10, wherein said secondphoto-detector configured to obstruct a second predefined portion of theat least one defined wavelength of light impinging upon said secondphoto-detector comprises: at least one photo-detector constructed toprovide a substantially neutral density filter that utilizes at leastone of absorption and reflection.
 17. The system of claim 10, whereinsaid second photo-detector configured to obstruct a second predefinedportion of the at least one defined wavelength of light impinging uponsaid second photo-detector comprises: at least one photo-detectorconstructed to provide a substantially neutral density filter thatfilters substantially ½ of the light impinging upon said secondphoto-detector.
 18. The system of claim 10, wherein said secondphoto-detector configured to obstruct a second predefined portion of theat least one defined wavelength of light impinging upon said secondphoto-detector comprises: at least one photo-detector constructed toprovide a substantially neutral density filter that filters a definedportion of photons at least partially composing the light impinging uponsaid photo-detector.
 19. The system of claim 1, wherein said secondphoto-detector sensitive to the at least one defined wavelength oflight, said second photo-detector being positioned along a path ofunobstructed light passing through the first photo-detector onto thesecond photo-detector comprises: a first portion having alight-receiving surface and a light-transmitting surface; and a secondportion having a second light-receiving surface proximate to thelight-transmitting surface of said first portion.
 20. The system ofclaim 1, wherein said second photo-detector sensitive to the at leastone defined wavelength of light, said second photo-detector beingpositioned along a path of unobstructed light passing through the firstphoto-detector onto the second photo-detector comprises: a first portionhaving a light-receiving surface and a light-transmitting surface; and asecond portion having a second light-receiving surface facing thelight-transmitting surface of said first portion.
 21. The system ofclaim 1, wherein said second photo-detector sensitive to the at leastone defined wavelength of light, said second photo-detector beingpositioned along a path of unobstructed light passing through the firstphoto-detector onto the second photo-detector comprises: at least onephoto-detector in substantial alignment with at least part of said firstphoto-detector.
 22. The system of claim 1, wherein said secondphoto-detector sensitive to the at least one defined wavelength oflight, said second photo-detector being positioned along a path ofunobstructed light passing through the first photo-detector onto thesecond photo-detector comprises: a spectrally-dependent filterinterposed between said first and said second photo-detectors.
 23. Amethod of constructing a system comprising: forming a firstphoto-detector configured to obstruct a first predefined portion of atleast one defined wavelength of light impinging thereupon; and forming asecond photo-detector sensitive to the at least one defined wavelengthof light at a location along a path of unobstructed light passingthrough the first photo-detector onto the second photo-detector.
 24. Themethod of claim 23, wherein said forming a first photo-detectorconfigured to obstruct a first predefined portion of at least onedefined wavelength of light impinging thereupon comprises: forming acharge coupled device (CCD) that includes at least one charge coupleddevice permeable to a first defined portion of light impingingthereupon.
 25. The method of claim 23, wherein said forming a firstphoto-detector configured to obstruct a first predefined portion of atleast one defined wavelength of light impinging thereupon comprises:forming a complementary metal oxide semiconductor (CMOS) that includesat least one complementary metal oxide semiconductor permeable to afirst defined portion of light impinging thereupon.
 26. The method ofclaim 23, wherein said forming a first photo-detector configured toobstruct a first predefined portion of at least one defined wavelengthof light impinging thereupon comprises: constructing at least onephoto-detector to provide an optical filter having a passband includingat least one of a red, a blue, and a green visible light wavelength. 27.The method of claim 23, wherein said forming a first photo-detectorconfigured to obstruct a first predefined portion of at least onedefined wavelength of light impinging thereupon comprises: constructingat least one photo-detector to provide a substantially neutral densityfilter.
 28. The method of claim 23, wherein said forming a secondphoto-detector sensitive to the at least one defined wavelength of lightat a location along a path of unobstructed light passing through thefirst photo-detector onto the second photo-detector comprises: forming acharge coupled device (CCD) that includes at least one charge coupleddevice permeable to a second defined portion of light impingingthereupon.
 29. The method of claim 23, wherein said forming a secondphoto-detector sensitive to the at least one defined wavelength of lightat a location along a path of unobstructed light passing through thefirst photo-detector onto the second photo-detector comprises: forming acomplementary metal oxide semiconductor (CMOS) that includes at leastone complementary metal oxide semiconductor permeable to a seconddefined portion of light impinging thereupon.
 30. The method of claim23, wherein said forming a second photo-detector sensitive to the atleast one defined wavelength of light at a location along a path ofunobstructed light passing through the first photo-detector onto thesecond photo-detector comprises: constructing at least onephoto-detector to provide an optical filter having a passband includingat least one of a red, a blue, and a green visible light wavelength. 31.The method of claim 23, wherein said forming a second photo-detectorsensitive to the at least one defined wavelength of light at a locationalong a path of unobstructed light passing through the firstphoto-detector onto the second photo-detector comprises: constructing atleast one photo-detector to provide a substantially neutral densityfilter.
 32. The method of claim 23, wherein said forming a secondphoto-detector sensitive to the at least one defined wavelength of lightat a location along a path of unobstructed light passing through thefirst photo-detector onto the second photo-detector comprises:constructing at least one photo-detector to have substantial alignmentwith at least part of the first photo-detector.
 33. The method of claim23, further comprising: positioning a light-transmitting surface of thefirst photo-detector proximate to a light-receiving surface of thesecond photo-detector.
 34. A method of detecting light comprising:obstructing a first predefined portion of at least one definedwavelength of light incident upon a first photo-detector; and detectingthe at least one defined wavelength of light with a photo-detector in asecond photo-detector positioned along a path of unobstructed lightpassing through the first photo-detector onto the second photo-detector.35. The method of claim 34, wherein said obstructing a first predefinedportion of at least one defined wavelength of light incident upon afirst photo-detector comprises: obstructing the first predefined portionof the light with a charge coupled device (CCD) in the firstphoto-detector.
 36. The method of claim 34, wherein said obstructing afirst predefined portion of at least one defined wavelength of lightincident upon a first photo-detector comprises: obstructing the firstpredefined portion of the light with a complementary metal oxidesemiconductor (CMOS) in the first photo-detector.
 37. The method ofclaim 34, wherein said obstructing a first predefined portion of atleast one defined wavelength of light incident upon a firstphoto-detector comprises: obstructing the first predefined portion ofthe light with a photo-detector without substantially altering arelative spectral distribution of energy in a second unobstructedpredefined portion of the light.
 38. The method of claim 34, whereinsaid detecting the at least one defined wavelength of light with aphoto-detector in a second photo-detector positioned along a path ofunobstructed light passing through the first photo-detector onto thesecond photo-detector comprises: detecting the at least one definedwavelength of light with a charge coupled device (CCD) in the secondphoto-detector.
 39. The method of claim 34, wherein said detecting theat least one defined wavelength of light with a photo-detector in asecond photo-detector positioned along a path of unobstructed lightpassing through the first photo-detector onto the second photo-detectorcomprises: detecting the at least one defined wavelength of light with acomplementary metal oxide semiconductor (CMOS) in the secondphoto-detector.
 40. The method of claim 34, further comprising:obstructing a second predefined portion of the light with aphoto-detector in the second photo-detector.
 41. The method of claim 34,further comprising: calculating an inferred brightness of light incidentupon the first photo-detector.
 42. The method of claim 41, wherein saidcalculating an inferred brightness of light incident upon the firstphoto-detector further comprises: calculating the inferred brightness oflight incident upon the first photo-detector in response to lightincident upon the second photo detector.
 43. The method of claim 34,further comprising: selecting one or more calculated inferredbrightnesses of light incident upon the first photo-detector as moreprobable inferences.
 44. The method of claim 43, wherein said selectingone or more calculated inferred brightnesses of light incident upon thefirst photo-detector as more probable inferences comprises: selectingone or more calculated inferred brightnesses of light incident upon thefirst photo-detector as more probable inferences in response to at leastone photo-detector indicating a saturation.
 45. The method of claim 43,wherein said selecting one or more calculated inferred brightnesses oflight incident upon the first photo-detector as more probable inferencescomprises: selecting one or more calculated inferred brightnesses oflight incident upon the first photo-detector as more probable inferencesin response to at least two calculated brightnesses of light incidentupon the first photo-detector.